The present invention relates to an elevator system, and particularly to an elevator system in which a receiving unit is installed in a counter weight.
Japanese Patent Application Laid-Open No. 57-121568, discloses an elevator system in which a drive unit is installed in a counter weight of the elevator. A primary side of a linear motor and an inverter, and a battery charger are installed in the counter weight in this elevator system. This battery charger is connected to a main electric power source across a sonnet connector, when the counter weight stops at the bottom position, and-electric power is supplied to the battery charger.
Further, the Japanese Patent Application Laid-Open No. 5-294568 indicates that, when the elevator-car arrives at the stop floor, electric power is supplied to the elevator-car in a non-contact way.
It is required to stop the counter weight at a power feeding position with accuracy in order to feed electric power to the counter weight. Generally, the elevator-car is designed so as to stop accurately at each of the floors. However, to accurately stop the counter weight at a predetermined position has not been given consideration. As a result, there is a concern that it will not be possible to stop the counter weight accurately at the power feeding position, for example, because of rope expansion, making it impossible to supply electric power to the counter weight. There is no consideration of the problem which makes it impossible to supply electric power to the counter weight because of such rope expansion in Japanese Patent Application Laid-Open No. 57-121568.
In addition, mechanical parts are connected when feeding power, and the separation of the mechanical parts is repeated during the use of the system.
In the technology described in Japanese Patent Application Laid-Open No. 5-294568, it is not required to stop the counter weight with a high degree of accuracy because the electric power is fed to the elevator-car side. Thus, no consideration has been given to the problem of stopping the counter weight with high accuracy in consideration of the possibility of rope expansion caused by the use of the elevator.
An object of the present invention is to provide an elevator system in which electric power can be surely supplied to the counter weight of the elevator.
In order to attain the above-mentioned object, the elevator system of the present invention includes a receiving means for receiving electric power from a feeding means provided in a hoistway, an inverter for converting the received electric power into ac power, a motor connected to an ac side of the inverter for driving a counter weight in up and down directions, a means for detecting a position of the receiving means; and a means for controlling the inverter on the basis of the position detected by the position detecting means. The counter weight carries the receiving means, the inverter, and the motor.